Approach computer for aircraft

ABSTRACT

An approach computer device is provided for an aircraft approaching a landing field to enable the pilot to have before him during the approach a device which shows the distance to the landing field and, correlated with that distance, the altitude at which the plane should be flying at such distance. The distance to be flown is set as the plane passes over the final approach fix from which the plane is to approach the field at a constant rate of speed. The device is calibrated to provide a constant rate of descent, such as 500 feet per minute.

United States Patent Nealon- APPROACH COMPUTER FOR AIRCRAFT [72]Inventor: Ivan W. Nealon, 364 Darrell Road,

Hillsborough, Calif. 94010 22 Filed: Nov. 19, 1970 21 App1.No-.: 91,063

[56] References Cited UNITED STATES PATENTS Fallis ..235/61 B German..235/61 NV Watson ..73/178 [451 Oct. 3, 1972 Primary Examiner-RichardB. Wilkinson Assistant ExaminerEdith Simmons Jackmon Attorney-Belchofiand l-loppe [57] ABSTRACT An approach computer device is provided for anaircraft approaching a landing field to enable the pilot to have beforehim during the approach a device which shows the distance to the landingfield and, correlated with that distance, the altitude at which theplane should be flying at such distance. The distance to be flown is setas the plane passes over the final approach fix from which the plane isto approach the field at a constant rate of speed. The device iscalibrated to provide a constant rate of descent, such as 500 feet perminute.

7 Claims, 5 Drawing Figures PATENTEDncI 3 m2 SHEET 1 OF 2 ATTOKNEV5 IPATENTED BT m 3.695.034

SHEET 2 OF 2 INVENTOR.

, BY IVAN .w. NEALON PIE.- .5. w

ATTORNEYS APPROACH COMPUTER FOR AIRCRAFT BACKGROUND OF THE INVENTION Theapproach phase of instrument flight is a relatively complex operationwhich requires the operation of many electronic and electromechanicalpieces of equipment. Commercial airlines are usually thought of as beingwell equipped but many general aviation aircraft have a limited amountof equipment which results in greater demands being placed upon thepilot.

' Similarly, the major air carrier airports have a full complex ofinstrument facilities to assist aviation, but the lesser airports havevarying amounts of navigational aids for instrument flight.

The best and most sophisticated instrument approach aid currentlyavailable is the ILS (Instrument Landing System). The ILS consists of aradio transmitter at the airport which, in effect, transmits two beamsoutward in the direction in which an airplane will approach. Theaircraft receiving the signal has instrumentation which will indicate tothe pilot both the direction in which he should fly in a horizontalplane and the glide slope he should fly in the vertical plane.

The problem is that many airports do not have ILS systems. In additionmany aircraft have equipment for receiving the horizontal portion of theILS, but not the glide slope portion. Other radio facilities such asADFs (Automatic Direction Finders), marker beacons and commercial radiostations can also be used for instrument approaches, but all of thesehave a more limited accuracy and place greater demands on the pilot.

In the interest of safety, it is not desirable to rely on a single pieceof equipment but to have various pieces of equipment capable ofproviding cross checks on the primary system. In this environment, thepilot needs all the help he can get. The approach computer of thisinvention is intended to reduce pilot workload and anxiety by serving asan additional navigational aid for the approach phase of a landing.

SUMMARY or THE INVENTION The approach computer of this invention isbasically a timing device capable of measuring the time from a knownposition. However, rather than being calibrated in hours, minutes andseconds as in a clock, one dial is calibrated to indicate at any pointin time the distance which remains to be travelled during the approachat a certain ground speed while another dial is calibrated to indicateat the same point in time the altitude at which a above sea level. a

Any type of timing device can be used so long as it is made consistentwith the scales to be used. The distance scale may be calibrated instatute miles, nautical miles; or kilometers and should be consistentwith the airspeed indicator in the airplane. Similarly, the altitudescale can be calibrated in feet or meters and should be consistent withthe altimeter in the aircraft.

I specific ground speed consistent with the timer employed. If the timerrate is variable, then the aircraft ground speed and descent rate can bevaried. The dials may also be interchanged with other dials havingdifferent ground speed and descent rates.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing onearrangement of the approach computer dial arrangement.

FIG. 2 is a side view of the device shown in FIG. 1.

FIG. 3 is a plan view of the device in reduced scale, showing the devicein use.

FIGS. 4 and 5 are, respectively, exploded and plan views showing otherdial arrangements which can be employed in the approach computer deviceof this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring particularly to FIGS.1 and 2, the approach computer of this invention includes a timingdevice, generally indicated at 6. The device includes a knob or pointer7 mounted upon a shaft 8 which is rotated by the timing device in acounterclockwise direction in FIG. 1. A collar 15 is rotatably mountedon the shaft and provides a support for other elements of the device.The device includes a fixed outer dial 9 calibrated in nautical miles.In the form shown, the tim- -ing device has a total escapement time of 6minutes.

Mounted rotatably on the collar 15 is an inner rotatable dial 10 whichis calibrated in hundreds of feet to indicate the altitude. Referring toFIG. 2, dial 10 is rotatably mounted on the collar 15 between washers 11and 12 under the bias provided by spring friction washer 14. Thisassembly is held in place by a double lock nut assembly indicated at 16and which are engaged with threads on the collar.

In use, the dial 10 is first rotated to indicate the elevation of thefield at which the landing is to be achieved, this value being placedopposite the zero indicia 21 on the outer dial. As the aircraft passesover the initial approach point, the pointer 7 is manually rotatedclockwise until it is opposite the distance in nautical miles from thedestination. This energizes the timing device, causing the pointer torotate counterclockwise. As the distance to the destination pointdiminishes, similarly the reading of altitude diminishes, this beingusually established at 500 feet per minute. If the altitude reading ismore or less than the altimeter reading, the pilot alters his rate ofdescent until the altimeter reading corresponds with the altitudeindicated by the approach computer. In the form shown, the fixed dial 9was based on a speed of knots and this gives a total distance scale of12 nautical miles. As the distance diminishes, so does the reading ofthe pointer over the altitude scale until finally, when the plane is atthe destination point, the altitude will be that of the field at thedestination point, at zero distance.

In that form of the invention shown in FIG. 3, the outside dial 31 isfixed. This dial is calibrated in distance from the destination point asin the form shown in FIG. 1. However, the inside dial 32 is fixed but isrotatable so that the field elevation can be set. in

against the index 34 provided upon the outer dial 31. The outer dial 31is calibrated for distance. In operation, the pilot, having adjusted thealtitude dial 32 for the field elevation, turns the knob pointer 33 tothe distance locating the aircraft in relation to the landing field. Theknob pointer 33 rotates counterclockwise and one can then read bothaltitude and distance by observing the position of the knob pointer insimultaneous relation to both dials.

In that form of the invention shown in FIG. 4, the inner dial 41 iscalibrated in hundreds of feet to show the altitude. This dial ismounted upon the knob and can be rotated with respect to the knob 44 forthe purpose of setting in the field elevation prior to the approach. Inthis form of the invention, however, once inner dial 41 has been set inposition to indicate the field elevation, the inner dial 41 rotates withthe knob. The distance from the field is then read on the outside scaleat the end of the knob pointer as the knob pointer rotatescounterclockwise. The altitude information is read on the middle scaleagainst the indicator 42 which is provided at the top of the outsidescale at zero distance.

In that form of the invention shown in FIG. 5, the outer dial 51 isrotatable on a supporting shaft and is calibrated in units of elevation.The inner dial 52 is calibrated in units of distance. With the two dialsfixed initially at the distance from the landing place and with fieldelevation set in, the pointer 53 indicates the desired elevation at theattained distance at any interval of elapsed time.

In another form of the invention, the outer dial is calibrated to showthe altitude while the inner dial is attached to the knob and iscalibrated in distance. The

outer dial is rotatable on the collar to set the field elevationopposite the 0 distance index of the inner dial. The inner dial rotateswith the knob timer and the altitude is read from the pointer and thedistance is read at a fixed distance index on the dial.

1 claim: I

l. A computer for use in aircraft for correlating the distance to betravelled by an aircraft moving at a predetermined speed from a fixedpoint on an: approach to a landing field with the altitude to bemaintained by the aircraft during the approach to the field, comprisinga clock mechanism having a face, a shaft extending from the clockmechanism through the face thereof and rotatable by said clockmechanism, a pair of dials each having a different diameter and mountedconcentrically about said shaft at said face, one of said dials havingsuitable indicia thereon for indicatingthe distance to be travelled andthe other of said dials having suitable indicia thereon to indicate thealtitude to be maintained, said dials being mounted for relativerotation of one to the other, a pointer mounted on said shaft forrotation therewith and movable with respect to at least one of saiddials, and one of said dials being movable relative to a reference markon the other dial to indicate the altitude of the landing field, so thatthe distance to be travelled and the altitude to be maintained can becorrelated one to the other.

2. A computer as in claim 1, wherein said one dial with distance indiciathereon is larger in diameter than the other dial and is fixed to theface of the clock mech ism.

3. computer as in claim 2, wherein the pointer is movable relative toboth dials to give an indication of both the altitude to be maintainedand the distance to be travelled.

4. A computer as in claim 2, wherein said other dial with altitudeindicia thereon is connected to move with said pointer.

5. A computer as in claim 1, wherein said other dial with altitudeindicia thereon is larger in diameter than said one dial and isrotatably mounted about said shaft on the face of said clock mechanism.

6. A computer as in claim 5, wherein said pointer is movable relative toboth dials to give an indication of both the altitude to be maintainedand the distance to be travelled.

7. A computer as in claim 5, wherein said one dial with distance indiciathereon is connected to move with said pointer.

Notice of Adverse Decision in Interference In Interference No. 98,320,involving Patent No. 8,695,034, I. W. Nealon, APPROACH COMPUTER FORAIRCRAFT, final judgment adverse to the patentee was rendered May 21,1976, as to claims 1, 5 and 6.

Notice of Adverse Decision in Interference In Interference No. 98,320,involving Patent No. 3,695,034, I. W. Nealon, APPROACH COMPUTER FORAIRCRAFT, final judgment adverse to the patentee was rendered May 21,1976, as to claims 1, 5 and 6.

[Oyficz'al Gazette November 30, 1976.]

1. A computer for use in aircraft for correlating the distance to betravelled by an aircraft moving at a predetermined speed from a fixedpoint on an approach to a landing field with the altitude to bemaintained by the aircraft during the approach to the field, comprisinga clock mechanism having a face, a shaft extending from the clockmechanism through the face thereof and rotatable by said clockmechanism, a pair of dials each having a different diameter and mountedconcentrically about said shaft at said face, one of said dials havingsuitable indicia thereon for indicating the distance to be travelled andthe other of said dials having suitable indicia thereon to indicate thealtitude to be maintained, said dials being mounted for relativerotation of one to the other, a pointer mounted on said shaft forrotation therewith and movable with respect to at least one of saiddials, and one of said dials being movable relative to a reference markon the other dial to indicate the altitude of the landing field, so thatthe distance to be travelled and the altitude to be maintained can becorrelated one to the other.
 2. A computer as in claim 1, wherein saidone dial with distance indicia thereon is larger in diameter than theother dial and is fixed to the face of the clock mechanism.
 3. Acomputer as in claim 2, wherein the pointer is movable relative to bothdials to give an indication of both the altitude to be maintained andthe distance to be travelled.
 4. A computer as in claim 2, wherein saidother dial with altitude indicia thereon is connected to move with saidpointer.
 5. A computer as in claim 1, wherein said other dial withaltitude indicia thereon is larger in diameter than said one dial and isrotatably mounted about said shaft on the face of said clock mechanism.6. A computer as in claim 5, wherein said pointer is movable relative toboth dials to give an indication of both the altitude to be maintainedand the distance to be travelled.
 7. A computer as in claim 5, whereinsaid one dial with distance indicia thereon is connected to move withsaid pointer.